There could be several reasons that trigger QuickBooks error code 6000 and the leading ones are corrupted TLG file, improper installation, or damaged company file. To eliminate QuickBooks error 6000 you may try the following measures.
· Firstly, you will need to re-configure your firewall or antivirus program. Open the QuickBooks database manager, locate the port monitor tab and then identify your QuickBooks version. Note down the firewall port number, go to the advance settings, click on the inbound option and then select a new rule. Click next to finish the process.
· Next, you may try to rename the .ND and .TLG files. You may add .OLD at the end of the extension name. After that, you may reopen QuickBooks and verify if the error has been resolved.